Permanent ballast on 26M

[Bertil Rafting]

Does someone knows what the permanent ballast consists of. I have meusured on the drawings and gets appr 0,14 m3 volume. Then the density gives appr 970 kg / m3, and then it must be water
Could that be true??

[schoeni]

Hi Bertil,
the permanent ballast is just sand!
Rainer

[kurz]

Hi Bertil,
the permanent ballast is just sand!
Rainer

Unfortunately it is true. I preferred lead... especially kind of Battery lead

Would be great tu put some batteries there. Great for the power and while trailering...

[Bertil Rafting]

How do you know that it is sand. Have you seen it or how do you know it? Don't mind me for asking as sand density is appr 1600 kg/m3, so the volyme should be appr 85 liters, not 140 liters as I tried to measure.
Thank you!

[kadet]

It is not pure sand but sand impregnated in resin for a total weight of 136 kilograms. And from the drawings, unless your have technical spec drawings, I don't know how you could accurately measure the volume as the permanent ballast is contained within the water ballast tank and from the line drawings you might be able to measure width and height but there is no length shown

[Tomfoolery]

The published spec is 136 kg permanent ballast, and 521 kg water ballast, as kadet stated. That's from the brochure.

[Bertil Rafting]

I have got the length 1,2 meter by meausuring inside the boat. I think it will be appr 25% polyester and the rest is sand. That will give a volume of appr 88 m3. Thank you. I now know enough to make a decision. I have put a leadkeel weighing 210 kg under the centerboard, so I do not need the permanent ballast. Thinking of taking it away and that will give place for another 88 kg of water in the movable ballast.So when it is really vindy I will have the righting moment from the keel and the movable ballast and that will make my 25M rather stiff by only adding to the trailering weight 210 - 136 = 74 kg.
Bertil

PS 1. Of course I had to make a stronger CB and strengtened the CB-case.
2. The keel i made is not a bulb but a surpressed keel with height 27 cm. A keel is much better than a bulb as it makes a better aspect ratio and increasing lateral resistent by appr 45% at speed 5 knots and heeling 20 degrees.

[BOAT]

Huh, I thought the M was a Dagger Board, Oh well they told me 300 pounds of sand and resin mixed together in a waterproof block around the "Dagger Board" opening and 1150 pounds of water. That's 1450 pounds.

If you have a 450 pound keel and 1150 pounds of water that's 1600 pounds. That would be more than enough I assume.

Is 1450 pounds a normal amount of ballast for a boat? (Or is that really light?)

[kadet]

Is 1450 pounds a normal amount of ballast for a boat? (Or is that really light?)

For a trailer sailer that is high. But most trailer sailers use lead or iron as ballast so to still be trailerable they cannot have as much ballast as they cannot dump their ballast like the Mac can . For example a Sonata 26 has 227kg / 500lbs in a weighted centre board.

[Bertil Rafting]

Sorry i wrote 88 m3, but I meant 88 dm3=liter,
Bertil

[sailboatmike]

Water ballast in the bilge is in reality highly uneconomic in terms of weight to righting moment, however it does allow un to have a 26 foot boat with around 100Kg or more of motor hung on the back and still be under 2000kg (4400lb) .

Most of the traditional ballasted TS's of the same size require much heavier trailers and all the extra cost involved of electronic brake activators etc.

Personally I would of loved to have a mixture of weighted centerboard and water ballast to have a bit of the best of both worlds, but that would of increased production costs and make it a real struggle to keep under the magic 2000Kg trailer mark we have in Australia.

From a quick off the top of the head calculation water ballast is around 33% less effective in righting moment as weight lower down

[BOAT]

The GZ curve for the MAC 26 M is actually better than the Hunter water lead hybrid boat - the Area of Positive Stability on the M was also larger than the Hunter.

The Righting moment curve just looks a little strange on the M boat because it peaks a little later than most other boats - but it's Angle of Vanishing Stability is much better than most trailer boats. The M pops well at 120 degree AH whereas the Hunter is under water at that Angle.

[Highlander]

U should not remove the permanent ballast it also doubles up as to re-enforce the D/B trunk base from impact damage & gives it more strength it,s part of the boat,s major structure design

J
PS Watch the promo vid

[Bertil Rafting]

Highlander:
-I will think about to take away the permanent ballast next winter when onshore.
-It would be nice to save 136 kg trailerweight and when sailing without ballast. When it is really windy I also can add 88 kg to the orginal ballast.
Bertil

PS I will use an electric winsch to lower und take up the CB with the 200 kg keel.

[Highlander]

remember that 300# ballast was added to give the more rounded hull more stability

J